My invention relates to the art of recording and reproducing digital information on and from record media typically including digital audio. tape packaged in cassette form. More particularly, my invention pertains to how to individually identify a series of tunes or other segments of information recorded on each digital audio tape cassette or the like, in order to make possible the selective reproduction of such information segments. Still more particularly, my invention concerns a method of, and means for, writing start marks in selected positions between prerecorded information segments preparatory to the writing of serial program numbers in such selected positions.
It has been standardized with digital audio tape apparatus to record digitized audio or other user information thereon along with what is known as "subcode", such as program numbers and time code. The program numbers are appended sequentially to successive tunes or other information segments recorded. For example, the program number "1"0 may a be attached to the first recorded tune, the program number "2" to the second, and so forth. Such program numbers are of immense help in later searching through the recorded tunes and quickly finding any desired one for reproduction.
Rarely, however, does the user record tunes on the complete length of virgin tape in a single recording session. He will more usually record one or more tunes on part of the tape and then, later, will record additional tunes on the remaining tape length. In that case the same program numbers "1", "2",. . . will be attached to the tunes recorded on the same tape during the second, as well as any subsequent, recording session. The program numbers are no longer sequential throughout all the recorded tunes. Therefore, unless the tunes are renumbered sequentially, any one of them cannot possibly be located in a standard search mode.
Inazawa et al. U.S. Pat. No. 4,641,208, assigned to Sony Corp. of Tokyo, Japan, represents a conventional solution to the problem of how to serially append program numbers to the tunes recorded in two or more sessions. It teaches the recording of temporary start marks, rather than program numbers, with the tunes recorded during the second and any subsequent session. The start marks are utilized for searching through the recorded tunes in subsequently rerecording program numbers in an orderly sequence in their steads. Japanese Unexamined Patent Publication No. 61-258357, filed by Sony Corp., teaches how to record the start marks exactly in preassigned positions and for a preassigned time, on digital audio tape.
Although these known solutions are satisfactory in their own ways, I still object to them for the following reasons. Program numbers, and therefore start marks, too, must be recorded between the prerecorded tunes. Accordingly, the user has to reproduce at least parts of the prerecorded tunes for finding their beginnings or ends and for determining proper positions for writing start marks between the tunes. The noted prior art approaches have forced the user to rely solely on his auditory sensation for the determination of positions to be stark marked, as well as for the subsequent amendment, if necessary, of the selected positions. It has therefore been a very difficult and time-consuming task for the user to write start marks in appropriate positions between all the tunes recorded on a single length of tape in two or more sessions.